Crazy Pacific cyclone
Crazy Pacific cyclones are tropical cyclones monitored by the M99 Meteorological Center in the Pacific Ocean. They form both north and south of the equator at any time of year, but activity in the north is more likely from May through December, and activity in the south is more likely from November through June. Formation is most common in the tropical regions, but storms can form further poleward in the subtropics and rarely in the far north/far south, with storms sometimes making landfall in Alaska and Antarctica. Storms are able to cross the equator, but will undergo significant weakening and may or may not be able to switch their direction of rotation and survive. Each year, 0-3 storms typically pull off such a feat. Category 5 equivalent storms are not uncommon and each of the four basins usually sees at least one every year. Storms with pressures below 870 hPa occur sparsely, typically once every 2-3 years for the whole Pacific; such storms are capable of deepening to extreme levels beyond that point. Basins The Pacific is divided into four basins: * Northwest Pacific (NWPac; north of equator, east coast of Asia to 180°) * Northeast Pacific (NEPac; north of equator, 180° to west coast of Americas) * Southwest Pacific (SWPac; south of equator, 140°E to 140°W) * Southeast Pacific (SEPac; south of equator, 140°W to west coast of Americas) Equatorial Crossing Steering currents often shift towards crossing the equator, with some storms actually doing so. The opposing Coriolis force will cause storms to steadily weaken until they either degenerate or complete a Coriolis Reversal Eyewall Replacement Cycle. A couple storms may survive crossing the equator each year, keeping their names, and sometimes restrengthening back to where they were prior to the crossing. 'Coriolis Reversal Eyewall Replacement Cycle (CRERC)' Storms usually need to be strong in order to survive crossing the equator and fully change their direction of rotation through a CRERC. Upon crossing the equator, a crazy Pacific cyclone, which is dubbed a tropical anticyclone after the crossing, will start to weaken as the opposing Coriolis force acts against it. The slower moving outer bands of the anticyclone will be the first parts of the storm to switch direction, followed by a propagation inwards from friction combined with the Coriolis force. The eyewall will gradually slow down from the force acting against it until its inertia can no longer sustain its anticyclonic rotation, at which point it collapses. In order for a CRERC to complete, an inner band has to switch directions and form an outer eyewall (cyclonic eyewall) before the anticyclonic eyewall collapses. If the anticyclonic eyewall collapses before a cyclonic eyewall is formed, the storm will lose its defined circulation and degenerate to a remnant low, which may or may not regenerate under a different name. The anticyclonic eyewall does not take long to collapse after the formation of a cyclonic eyewall. Once a CRERC is complete, the storm, now a tropical cyclone once again, will typically have an abnormally large eye, usually larger than what a regular ERC may produce. Weaker storms (category 2 equivalent and lower) usually are unable to complete a CRERC. Storms that do complete a CRERC are normally much weaker once the process completes than they were before crossing the equator, and restrengthening isn't guaranteed. Typically, the stronger a storm is upon equatorial crossing, the stronger it will be upon completing a CRERC, but even very strong storms can sometimes come out as minimal hurricane-equivalent cyclones. The process is quite sensitive to environmental factors, and even moderately unfavorable conditions can cause a strong cyclone to fail to complete a CRERC. The reversal process can also sometimes happen unevenly and create wind shear, which could result in failure. 'Double-Crossing' Storms sometimes cross the equator twice, which comes in three flavors. First is the aborted crossing, where a storm re-crosses the equator without ever reversing its direction in the other hemisphere. Depending on how long the storm was in the other hemisphere, the storm may have weakened somewhat and may be partially through a CRERC process. Second is the full double-crossing, a rare event when a storm twice completes a CRERC. Only a handful of storms on record have ever done this. Third is the remnant re-crossing, where a storm that failed to complete a CRERC re-crosses the equator after degenerating. Any regeneration of such a system will still acquire a new name, however, even in the storm's original basin. Naming WIP https://docs.google.com/spreadsheets/d/12r37VppGQMaGIcQavqU7t5aOP1xJO6y1EdT5W2RZ5_s/edit?usp=sharing Category:Pacific Hurricanes Category:Tropical cyclones near the equator Category:Basins Category:Unusual tropical cyclones